Im having trouble grapshing this concept. Can anyone please explain what voltage across two points means. Does it mean that one point is at a higher potential energy than the other point? Does it mean that the charges present are closer to the point a, and thus produce a stronger net force when a charged body is placed at point a, than at point b? Im trying to see how you get a potential inside a wire. I know you need a battery, but what does that mean in terms of the charges inside the wire? U(potential) = 1/4pi epsilon * q q0 / r^2. and V = 1/4pi epsilon * q /r^2 How does the definition of potential and potential energy relate to a circuit. Lets juse use a simple one, a battery and a light bulb or a resistor or something. How do these equations apply, more imporantly what is the MEANING of it? I dont see how we can talk about voltage in a wire to begin with. The book does cases of voltage where charge is not moving and is treated as points or a continuous distribution. In a wire, the charge is moving around the circuit.